Most closely related to sea urchins, sea stars (aka starfish), sea lilies, and sand dollars, these bottom-dwellers range from as small as one inch long up to six feet.

Bioluminescence first evolved in animals at least 540 million years ago in a group of marine invertebrates called octocorals, according to the results of a new study from scientists with the ...

This ability has independently evolved at least 94 times in nature. Bioluminescence is involved in multiple animal behaviors including communication, courtship, camouflage, and hunting.

Hundreds of plants, fungi, and animals can do it. Now scientists think bioluminescence may have evolved 540 million years ago in Earth’s ancient oceans.

Kayakers in Bahia Mosquito create bioluminescent wakes in Vieques, Puerto Rico, Sept. 23, 2000. The water in the bay is charged with micro-organisms that emit blue light when agitated.